net_sched: Add accessor function for packet length for qdiscs

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index 1d97fa4..23d258b 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -27,7 +27,7 @@
 {
 	struct fifo_sched_data *q = qdisc_priv(sch);
 
-	if (likely(sch->qstats.backlog + skb->len <= q->limit))
+	if (likely(sch->qstats.backlog + qdisc_pkt_len(skb) <= q->limit))
 		return qdisc_enqueue_tail(skb, sch);
 
 	return qdisc_reshape_fail(skb, sch);